All photographs unless otherwise stated or credited belong to the "Sidney Clarence Gudsell Photographic Trust"
Photographer's negatives - the most common question I am asked relates to the current location of photographer's negatives - see this post.
I'm not able to provide any information about photographers other than that on this site. I'm am also not able to date photographs or assist you in identifying people in photographs you may have. I am unable to assist in locating the current location of business records of any photographer.
I recommend the Auckland City Library's website for more information about New Zealand photographers - http://www.aucklandcity.govt.nz/dbtw-wpd/photographers/basic_search.htm